4.9x^2-80x-102=0

Solution for 4.9x^2-80x-102=0 equation:

4.9x^2-80x-102=0

a = 4.9; b = -80; c = -102;
Δ = b2-4ac
Δ = -802-4·4.9·(-102)
Δ = 8399.2
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-80)-\sqrt{8399.2}}{2*4.9}=\frac{80-\sqrt{8399.2}}{9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-80)+\sqrt{8399.2}}{2*4.9}=\frac{80+\sqrt{8399.2}}{9.8}
$